Nitric oxide (NO) is now recognized as a signaling molecule in biology and has been implicated in the function of virtually every organ system in mammals. It is known that NO relaxes blood vessels, intestines, airways and skeletal muscles and plays a role in memory, sexual behavior and host defense. On the other hand, excessive production of NO has been implicated in organ dysfunction, degenerative disease and promotion of cancer. Arthritis, ulcerative colitis, Alzheimer's disease, congestive heart failure, septic shock and atherosclerosis are disorders in which NO may play a pathogenic role.
It is recognized that there is normally a certain amount of endogenously produced oxidative stress in mammals, i.e., the endogenous production of reactive oxygen species in the body, e.g., superoxide, hydrogen peroxide, hydroxyl radical, hypochlorous acid and singlet oxygen. This is thought to contribute to ageing, rheumatism, atherosclerosis, inflammation, respiratory distress syndrome, fibrosis, and development of infectious diseases such as AIDS.
Before the discovery leading to the inventions herein, it was not recognized that there is a nitrosative stress distinct from oxidative stress that affects mammals and also microorganisms which can be manipulated in a therapeutically effective manner, either by decreasing microbial, helminth or pathologically proliferating mammalian cell defenses against nitrosative stress or by imposing a nitrosative stress or by upregulating nitrosative stress defenses.